Vivaldi wrote Juditha Triumphans for the musically talented women of the Ospedale della Pieta, the Venetian orphanage with which he was associated on and off throughout most of his working life. The librettist, Giacomo Cassetti, described the work as a ''sacred military oratorio performed in times of war by the chorus of virgin singers, to be sung in the church of the Pieta''. The war was that into which Venice had entered against the Ottoman Empire and to which reference is made both in the body of the Latin text and in a ''Carmen Allegoricum'' which accompanied the text of the work's first performance.